<?php

    abstract class UserType {

        public static $Guest = "Guest";
        public static $Customer = "Customer";
        public static $ProductManager = "Product Manager";
        public static $AccountingManager= "Accounting Manager";
        public static $Administrator = "Administrator";

        public static function Valid($value) {
            switch ($value) {
                case UserType::$Guest:
                case UserType::$Customer:
                case UserType::$ProductManager:
                case UserType::$AccountingManager:
                case UserType::$Administrator:
                    return TRUE;
                    break;
            }
            return FALSE;
        }

    }

?>